Steam-turbine



C. V. KERR.

STEAM TURBINE. 'APPLHCATlON FIL'ED SEPT.1.1917.

Patented Dec. 6, 1921.

3 SHEETS-SHEET 1.

C. V. KERR.

STEAM TURBINE.

APPLICATION FILED SEPT-t, 1911.

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C. V. KERR.

STEAM TURBINE.

TION FILED SEPT 1 1,399,215, Patented 1m. 6,1921. 3 EEEEEEEEEEEE 3- CHARLES V. KERR, OF AURORA,

ILLINOIS, ASSIGNOR TO THE AMERICAN WELL WORKS, OF AURORA, ILLINOIS, A CORPORATION OF ILLINOIS.

STEAM-TURBINE Specification of Letters Patent.

Patented Dec. 6, 1921.

Application filed September 1, 1917. Serial No. 189,320.

To all 207mm it may concern.

Be it known that I. Crmnnns V. KERR, a citizen of the United States, residing at Aurora, in the county of Kane and State of Illinois, have invented certain new and useful Improvements in Steam-Turbines, of which the following is a specification.

This invention relates to new and useful improvements in elastic fluid turbines, and more particularly to the class known as the multi-cellular type.

The objects of this invention are:

First, to construct a casing in sections between which rings containing the stationary buckets are clamped and the use of packing in the joints between the sections thereby obviated;

Second, to construct the diaphragms of sections permitting the nozzles to be accurately and inexpensively machined there in;

Third, to provide a comparatively inexpensive rotor and stator construction by the use of stamped metal buckets;

Fourth, to provide an improved joint between the diaphragms and the rotor;

Fifth, to provide an improved method of securing the rotor elements on the shaft, and

Sixth, toprovide a turbine construction in which standard parts are employed and ma chines for different conditions produced by simply varying the number of such standard or interchangeable parts.

My invention consists of structural features and relative arrangement of elements which will be hereinafter more fully and clearly described, and particularly pointed out in the appended claims.

Referring to the three sheets of drawings, in which similar reference characters indicate the same parts in the several figures;

Figure 1, is a longitudinal sectional view of a turbine embodying my invention;

ig. 2, is a transverse section on line II.II of Fig. 1;

Fig. 3, is an enlarged side elevation of a fragment of one of the diaphragms;

Fig; 4, is a development of a section on line IV--IV of Figs. 3 and 5;

Fig. 5, is a section on line V-V of Fig. 3;

ig. 6, is an enlar ed longitudinal section of a fragment of the central portion of one of the diaphragms and the adjacent parts;

Fig. 7, is a transverse section on line VII-VII of Fig. 6,;

ig. 8, is an enlarged fragment of Fig. 1;

Fig. 9, is a sectional and diagrammatic view, as on line IX-IX of Fig. 8, illustrating the operation of one stage of expansion;

Fig. 10, is a side elevation of a fragment of one of the reversing rings, provided with the stationary buckets and Fig. 11, is a perspective view of one of my improved buckets.

Referring to the drawings, the turbine, as illustrated, comprises a casing made 11 of a series of annular sections 15, and the intake head 16, and exhaust head 17, these heads being provided with bases 18 which support the turbine. The heads 16 and 17 have flanges which project beyond the section and are connected by bolts 19 which secure the parts of the casing together. Each of the sections 15, has an internal flange 20, the inner surface of which is cylindrical and is machined to fit the periphery of a diaphragmbetween the stages of expansion. It will be understood that the number of stages may be varied to suit the particular conditions and in the turbine illustrated there are four stages. The diaphragm 21 is secured to the head 16 by bolts 22, a fluid tight joint being provided at 23. The three diaphragrns 24 are alike and the nozzle construction in their peripheries is also like that of the diaphragm 21.

Each of the diaphragms 21 and 24 is secured in its corresponding casing section 15, by shrinking the latter on and by screws 25, shown most clearly in Fig. 5. The nozzle construction above referred to is shown most clearly in Figs. 3, 4; and 5, and each nozzle consists of a spiral of helical groove 26, which is preferably milled in the periphery of the diaphragm, the operation being practhe cutting of gear teeth. The diaphragms are also turned off as indicated at 27, and the flanges 20 are beveled at 28 to facilitate the entrance of the motive fluid into the nozzles and reduce losses through wire-drawing. The corners 29 of the nozzles are rounded for the same purpose.

Arranged between the sections 15 and also between one of these sections and the exhaust head 17 are rings 30, preferably made of soft steel or bronze. The ends of the sections 15 are machined smooth and since these sections will usually be made of cast iron or other material harder than the rings 30, the clamping action of the bolts 19 will readily and with a certainty produce tight joints between the sections.

Each of the rings 30 is provided on its interior with slots 31, which may be milled and which are adapted to receive the buckets 32. (See Figs. 8, 9 and 10.) The slots 31 preferably extend at an angle about 7 /2 to the axis of the turbine and each slot receives the tab 33 of a bucket, the edges of the tab being riveted or rolled to secure the buckets in the slots. It will be observed that the buckets are dished and have their edges thinned to offer less resistance to the flow of the motive fuel. The ends 34, of the buckets are rounded and fit the concave periphery of the ring 35, onto which the ring'30 with all of its slots 31 filled, is shrunk, thereby the buckets.

The rotor of the turbine consists of a shaft 36 mounted in bearings 37, 38, preferably of the ring-oiling type and mounted on the heads 16 and 17, respectively. A coupling 39 is provided on one end of shaft 36 for driving any machine that is to be operated by the turbine. Where the shaft 36 passes through the heads 16 and 17, it is threaded. as indicated at 40 and 41and has screwed thereon the nuts or sleeves 42 and 43, of bronze or other material. The sleeves 42 and 43 rotate with the shaft 36 and to prevent leakage of the motive fluid alongthe surface of the sleeve, packings 44 and 45 are provided, these packings receiving lubricant from pockets 46 in the heads 16 and 17, and the pockets being supplied from cups 47 by pipes 48. These shaft threads 40 and 41 are also arranged right and left'hand so that the friction of packing 44and 45 on the sleeves 42 and 43, tends to tighten the sleeves against the hubs or collarsof the series of disks mounted on. the shaft between them.

The shaft 36 is also threaded at 49 to receive the spiral gear 50, whichis secure by the lock nut 51. The gear 50 drives a gear 52 of a novel governor mechanism 53' which willbe fully described and claimed in another application.

Between the sleeves 42 and 43, the shaft 36 is provided with keys 54, (see Fig. 7), and carries a series of abutting collars 55 which are clamped in position by the sleeves 42 and 43. flange 56 to which a disk 57 is secured by rivets 58' or other suitable means. (See Alsoeach of the collars 55 has a counterbore at each end of a diameter slightly "largenthan the keyways 54. The effect isto form an annular space 79 betweeneaclrpair of collarsin which lubricant firmly securing valve,

Each of the collars 55 has a.

pushed ahead of the collar in assembling may collect without interferin with the spacing and alinement of the isks. The disks 57 are preferably bored out so as to have a press-fit on the collars 55 so that the centrifugal forces will not loosen the disks.

in order to provide fluid tight joints between the diaphragms 24 and the collars 55, the latter are turned true and smooth to make a running fit with collars 58 which bear against the diaphragms 24 on the annular surfaces 59 and are held from turning by one or more studs 60. (See Fig. 6.) The pressure of the motive fluid on the collars 58 maintans a tight joint on the surfaces 59.

Each of the disks 57 has a slotted periphery to receive the buckets, which are similar to the buckets 32 and are secured in the slots in the same manner as the buckets 32. From Figs. 1 and 8, itwill be observed that there is a disk 57 on either side of the ring 30, the buckets 61 of one of the disks being between the nozzles 26 and the buckets 32, and the buckets 62 on the other disk receiving the motive fluid from the buckets 32.

Rings 63, having concave inner surfaces are shrunk on over the buckets on the disks 58. A governor valve 64 is provided and the motive fluid or live steam flows from this through the passage 65,- into the steam chest 66 in the head 16. The motive fluid is then discharged series of nozzles 26 against buckets 61 of the rotor, from which it is passed to the reversing buckets 32, and then against the buckets 62, thereby completing-the first stage of the expansion. The motor fluid then flows through the successive stages and is eventually discharged into the chamber 67 of the head 17 from which it goes to the condenser; A. by-pass 68 is also provided to convey live steam from the valve 64, see Fig. .2, toone or more of the later stages on the discharge 1 side of the rotor members, the admission of the steam to these stages being through properly and correctly proportioned nozzles 70, controlled by valves 69, as shown 1n d Fig. 1.

In the use of nozzles for elastic motive fluids, it is known that if the final pressure due to expansion of the fluid inpassing through the nozzle is greater than-"the critical pressure which is about 57% of the ini-. tial absolute pressure 55% for superheated steam and 53% for gases, the weight of fluid discharged per second will depend upon both the. initial and final pressures. While, if the final pressure is less than the critical weight discharged tial pressure only. Hence in a turbine of the multicellular type, if connection by nozzle be made to stages havingpressures lower than the critical, then the tot 1 weight of 1 through the first for saturated steam, 1

pressure the 1 111 depend on the inimotive fluid so used can be predetermined and also its distribution to the various stages. Further, the motive fluid so bypassed can be put under control of the governor, as shown by Figs. 1 and 2, which will make the weights of fluid passing through the nozzles and admitted to steam chest 66 proportional to the load. Such use of the by-pass is intended to meet conditions of overload and under pressure, and the purpose of making connection to one or more stages is to avoid too great derangement of pressures in the stages affected.

Although I have shown each stage of the turbine as comprising two sets of rotatable buckets and one set of stationary reversing buckets, this combination may be varied. It may also be found desirable, in some instances, to make changes in the details of the specific construction of my preferred form of the invention, and I do not care to limit myself to these specific details, as they may be modified in many ways without departing from the spirit of my invention, and still accomplish the same results.

What I claim is 1. In an elastic fluid turbine, the combina tion of a casing consisting of a plurality of substantially abutting annular sections, heads closing the ends of said casing, a rotor including a plurality of bucket wheels, and one or more members provided with reversing buckets forming fluid-tight joints between the casing sections.

2. In an elastic fluid turbine, the combination of a casing consisting of a plurality of substantially abutting annular sections, heads closing the ends of said casing, a rotor including a plurality of bucket wheels, a member provided with reversing buckets and serving as packing in the joint between the casing sections, and bolts connecting said heads and clamping said member and said casing sections together.

3. In an elastic fluid turbine, the combination of a casing comprising heads for closing the ends of the casing, and one or more substantially annular sections between said heads, said heads and sections having counterbores at their abutting portions, a rotor, one or more members provided with reversing buckets and each member arranged between the casing sections and in the counterbore thereof, and means for clamping the sections of the casing together.

a. In an elastic fluid turbine, the coinbina tion of a casing comprising heads for closing the ends of the casing and one or more substantially annular sections each of which carries a diaphragm for separating two stages of the turbine, said heads and sections having alined counterbores at their abutting portions, a rotor, one or more members provided with reversing buckets and each member arranged in the counterbores or abutting casing sections and serving as a packing, and means for clamping the sections of the casing together.

5. In an elastic fluid turbine, the combination of a casing comprising one or more sub stantially annular sections, a rotor, a dia phragm provided with spirally arranged peripheral slots which constitute nozzles, and means whereby said diaphragm is held in one of said sections.

6. In an elastic fluid turbine, the combination of a casing comprising one or more substantially annular sections having an internal flange, one or more diaphragms each fitting within the said flange of a casing section and having spirally arranged peripheral slots which constitute nozzles, and a rotor having bucket wheels motive fluid from said nozzles.

7. In an elastic fluid turbine, one or more diaphragms formed of concentric circular sections, and one of the sections being provided where it joins another section, with spirally arranged transverse slots which constitute nozzles.

8. In an elastic fluid turbine, one or more diaphragms formed of a central disk and a ring shrunk on the periphery thereof, one of said parts being provided, Where it joins the other, with spirally arranged slots which constitute nozzles.

9. In an elastic fluid turbine, the combination of a rotary shaft, a plurality of keys extending lengthwise of said shaft, collars concentric with said shaft and engaged by said keys, radially extending flanges on said collars and bucket wheels fitted and secured to said flanges, and counterbores in each end of said collars larger in diameter than the keyways to form annular spaces for collection of lubricant in assembling.

10. In an elastic fluid turbine the com-' bination of a casing, a rotor shaft extending through said casing and having spaced oppositely threaded portions, a plurality of bucket wheels having abutting hubs secured on said shaft between said threaded portions, sleeves engaging said threaded portions and thereby clamping said hubs together, packing arranged in said casing about said sleeves and adapted to maintain by friction of rotation against said sleeves a desired axial position of said bucket wheels.

11. In an elastic fluid turbine, the combination of a rotary shaft, disks on said shaft, buckets carried by said disks and adapted to receive jets of motive fluid, a series of annular sections, a diaphragm fitting within each of said sections, nozzles for supplying jets of fluid to said buckets formed by cutting spiral slots in the periphery of said diaphragms, and means for holding the diaphragms within the annular sections thereby completing the nozzles.

12. In an elastic fluid turbine, the comwhich receive the tion of initial fluid pressure.

13. In an elastic fluid turbine, the cornbination of a series of annular sections, one or more nozzles constructed toiconvert pres sure into velocity and arranged to deliver motive fluid radially inward to a like number of said sections wherein the pressure is lower than the critical pressure of said 1110- tive fluid, a governor valve, a governor'valve case having a discharge chamber, a conduit for motive fluid connecting the discharge space in said valve case with said nozzles, and stop valvesin said conduit, thereby controlling the period of service, the distribution and the rate offlow of motive fluid.

In testimony whereof I affix my signature.

CHARLES V. KERR. 

